Gas-engine.



No. 629,904. Patented Aug. I, 1899. L. J. mm.

GAS ENGINE.

iAppXica-tion filed. July 20, 1897.

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N9. 629,904. Patenteq Aug. l, 1899.

L. J. HIBT.

GAS ENGINE.

(Application filed July 20, 1897.)

4 Sheats-Shaet' 2.

(No Model.)

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"0.629904; Patented Aug. 1, I899. .L. J. mm.

' GAS ENGINE.

Application filed July 20, 1897.) (No Model.) 4 Shaets8haet 3.

WITNESSES- IN VENT-13R.

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No. 629,904. Patented Aug. I, {899* L. J. HIRT. GAS ENGINE. (Application filed July 2 0, 2897.}

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UNITED STATES PATENT OFFICE.

\ LouisJ. HIRT, on nnooirtmn, MASSACHUSETTS.

GAS-ENGINE.

SPECIFICATION forming partof Letters Patent No. 629,904, dated August 1, 1899.

Application filed July 20; 18975 semi No. 645,221. (lilo model.)

. l We To a. whom it may concern: I

7 Be it known that I, LOUIS J. H131, a citizen of the United States, residing in Brookline, in the county of Norfolk and State of M assach of setts, have invented an Improvement in Gas- Engines, of which the following description, in connection with the accompanying draw ings, is a specification, like letters and figures on the drawings representing like parts.

This invention relates to a gas-engina'and has for its object to providean engine capa ble at the will of the operator of working as a two-cycle engine having a power-stroke for every revolution of the main shaft orjas a' four-cycle engine having a power-strokefor alternate revolutions of the main shaft. t

In accordance with this invention the en glue is provided with novel valves controlling the admission and exhaust of the gas to and from the cylinder and a novel mechanismfor operating the valves, which is capable of be-' ing worked at the will of the operator to control the flow of gas into and out of'the cylinder, so that the engine may by operated either as a two-cycle engine or as a four-cycle engine. These and other features of this invention will be'pointed out in the claims at the end of this specification.

Figure 1 is a side elevation of one form of gas-engine embodying this invention ;.Fig. 2, a top or plan view of the engine shown in Fig.1; Fig. 3, a detail in section of the igniter,

the section being taken on the line 3 3, Fig. 2; Fig. 4., a cross-section on the lines, 4 4,' Figs. 1 and 2, looking in the direction of the arrow in Fig. 1; Fig. 5, a cross-section on the irreg ular line 5 5, Fig. 1, lookingin the direction of the arrow thereon; Fig. 6, a cross-section on the line 6 6, Fig.1, looking toward; the

right; Fig. 7, a horizontal section on the line 7 7, Fig. 1; and Fig. 8, a side elevation ofthe engine shown-in Fig. 2, looking atthe oppo site side from that shown in Fig. 1.

In the present instance I have chosen to illustrate my invention as a double-acting engine, in which "A represents a cylinder secured, as by bolts A, to a frame A erected upon abase or foundation A The cylinder A (see Fig. 7) contains within it a piston 61., provided with a piston-rod a. and adapted to be reciprocated in the cylinder A by means of gas admitted into the cylinder at its opposite ends through the ports a? a which commu- 'nicate, respectively, withvalve-chambers 0. a containing balanced piston-rods a a,

the said valve-chambers communicating with a single inlet-port a (see Figs. 1 and 2,) to which in practice thegas-supply pipe is secured. The piston-valves a a? are of like construction and are preferably made as will now be described.

The piston-valve a is vertically arranged, and its lower part or half is of smaller diameter, so as to leave between it and the walls of the cylinder (0 an annular passage a for the gases admitted intothe said cylinder to encircle the valve and assist inbalancing the same. The lower orbotto'm end of the pistonvalve is beveled, as represented in Fig. 4c, and

i cooperates with a beveled seat2 at the bottom of the port a to thereby close the communication between the gas inlet or supply a and the port a The'piston-valve a. is provided with a valve-rod a, e ctended through a suitable stnffing-box a9, which forms the bottom of the cylinder 0;, and the said piston-rod a, within the lower part of the cylinder a is provided with 'a coun'terbalancing-piston a, the'purpose of which is to prevent the valve I a being lifted from its said seat. when the engine is running as a two-cycle engine.

. The valve-rod a has mounted upon it below the piston-valve a series of perforated j disks e to prevent flashing back and which,

as shown, are secured between the bottom of v the. piston-valve-and a washer a The valve-rod a, as represented in Figs.

land 4i, has'secnred to its lower-end a yoke or arm a provided, as shown, with a slot 1a (see dotted lines, Fig. 4, and full lines,

Fig. into which is extended an arm a" on a rock-shaft a, havingan arm a extended substantially diametrically opposite to the arm a and engaging a depending lug or arm a on a lever n for a purpose as will be described. The yoke or arm a is also engaged by a spring a, fastened to a stationary part of the engine and,.as shown, extended into a slot in thearm or. yoke a and which acts under normal conditions to keep the valve a seated. The valve of is designed to be automaticaliy governed by the speed of the engine, so as to vary the length of the valvestroke, and thereby the admission of the gas into the cylinder, and this result maybe effected in the following manner.

Referring to Figs. 1, 4:, and 6, the lever or arm 0, which engages the rocker-arm a is pivoted to the lower end of an arm Q23 of a bell-crank lever mounted on a shaft or pivot a and having its arm 0. connected bya link LL26 to an arm a, fastxon a rock-shaft c which is supported in suitable bearings a? a (see Fig. 1) and has a crank or arm a, (see Fig. 6,) joined by a link a to a sliding collar a of a governor G of any usual or desired construction.

The gases admitted into the cylinder A through the port or passage (1. are designed to pass out from said cylinder through an exhaust-port 1) into an exhaust-chamber 1), containing an exhaust piston-valve b the said exhaust-chamber having a main outlet-port 19 connected to the main exhaust-pipe b (Shown in Figs. 2 and 5.)

The piston-valve b has its upper end fitted to slide in the valve-cylinder b, and its lower part or end is made of smaller diameter to leave an annular passage b, so that the exhaust-gases may encircle the valve and substantially balance the same to thereby insure the exhaust-valve working under all conditions and irrespective of the pressure in the cylinder A.

The exhaust-valve b is provided with a valve-rod 19 having at its lower end a yoke or slotted arm 19 through which extends the end of a lever 5 (see Fig. 4,) pivoted at b to a depending arm or bracket b secured, as by bolts 1), to the bottom of the cylinder A. The yoke b is also engaged by a spring I), which normally acts to hold the exhaustvalve 11 to its seat I).

intothe cylinder A after compression, as will be described, is exploded by means of an igniter, preferably of the construction herein shown (see Fig. 3) and consisting of a cylinder 0, provided with a conical cap or head 0', having preferably a plurality of vents c and the said cylinder has a pipe or passage 0 communicating with the port a (See Figs. 3 and 7.) The cylinder 0 contains a 'piston 0 provided with'a stem or rod having a slotted arm or yoke a (see Fig. 5) engaged by an arm 0 on a' sleeve (see Fig. 1,) mounted loosely on a stud or pin 0 secured to the frame A the said lever having an arm 0 which is adapted to be engaged by cams 0 0 (see Figs. .2, 4, and 5,) as will be described. The piston 0 is normally elevated by the spring 0, attached at one end to the cylinder 0 and at its other end to the arm a".

The vented cap 0' is extended into a pipe 0 provided with a burner tube or jet 0 which in practice is connected to a suitable source of supply for the gas which is continuously burning at the mouth of the tube or jet c and thereby keeps the cap a heated sufficiently hot to ignite the gas admitted into 'or desired manner.

from the main shaft 0 by a spur-gear 0 in.

The gas admitted the cap 0 from the port a through the passage c on the downstroke of the piston 0 The vent-openings in the cap a afford opportunity for the piston c to expel the gases out of the capon the upstroke of the piston, and thereby avoid the accumulation of what may be termed waste or dead gases in the cap, and consequently insures the ignition of each charge of gas admitted into the cylinder A.

The gas-inlet valve a and its exhaust-valve b are adapted to be operated by double cams c 0 when the engine is operating as atwocycle engine, and when operating as a fourcycle engine the valve a is operated by a single cam c and the exhaust-valve b by a single cam 0 These cams are fast on a shaft 0 capable of being moved longitudinally to change the position of the constant and variable cams as desired with relation to the levers connected tothe valves.

The shaft 0 is rotated by a shaft 0 to which it is connected by a sleeve and a key 0 the sleeve being adapted to be moved longitudinally by a lever 0 forked at its end and pivoted at e and provided with suitable lugs to engage an annular groove in the said sleeve. The lever c is adapted to be locked in one or the other position in any suitable The shaft 0 is driven mesh with a spur-wheel 0 in turn fast to a beveled gear 0 which drives a beveled gear 0 fast on the shaft 0 The spur-wheel c and gear 0 are set two to one, so that the main shaft 0 makes two revolutions to one of the shaft 0 whereby single cams may opcrate the valves once every two revolutions of the main shaftand double cams every rev'olution.

The piston a may be connected to the main shaft 0 in any suitable or desired manner and is herein shown as connected to a sliding cross-head 0 (see Fig. 1,) joined by a connecting-rod e to a crank-pin 0 on a disk or crank 0, fast on themain shaft.

The engine can be started under load with the double cams c? 0 so that the engine will be operated by gas and air taken fromsuitablereceivers, not herein shown, but such as now employed with two cycle engines, in which the gas or mixture of gas and air is admitted into the piston -cylinder at each stroke of the piston and is exploded as soon as it is admitted into said cylinder.

When the engine is started and running, it may be converted at the will of'the operator into a four-cycle engine by shifting the shaft 0 so that the single cams c 0 will operate the valves once every two revolutions, and gas or a mixture'of gas and air will be admit-ted into the piston-cylinder at every other stroke of the piston and exploded at the beginning of the second forward stroke of the piston after being compressed on the return portion of the first stroke of the piston. As a result the engine possesses all the advantages of a two-cycle engine for starting under a load and of a four-cycle engine for economy when once started.

lrVhen the engine is working as a two-cycle engine, the gas-admission valveo and the igniter-piston o are operated substantially simultaneously, so thatthe gas is ignited as it enters the cylinder, and when working as a four-cycle engine the cams o and 0 are timed so that the gas is first admitted into thecylinder, then compressed, and when compressed it is exploded and expanded and then exhausted. V

In the present instance the engine is shown as a double-acting engine, provided at one end of the cylinder A with the inlet-ports and exhaust-port b and at the other end with like ports and parts cooperating therewith, together with an igniter, all of which parts are marked with the same letters as the parts at the opposite end of the cylinder with the affix a added.

If desired, my invention may be embodied in a single-acting engine.

By reference to Fig. 4 it will be seen that the cams e c are adapted to engage the upper surface or cross-piece 3 on the end of the lever 00 to open the gas-inlet valve a and that the position of the cross-piece 3 with relation to the said cams is determined by the speed of the engine through the governorv G, which turns the bell-crank lever on its pivot an, and thereby moves the lever a on the arm a, so as to present'more or less of the cross-piece 3 to the action of the cams, whereby more or less of the cams engage the crosspiece and thereby open the gas inlet valve more or less, according to the speed of the engine.

Then the engine is working as a four-cycle engine, the cam is shaped or timed to permit the gas-admission valve to cut off the supply of gas before the piston-reaches the end of its first stroke, the point of cut-0E be.- ing variable and controlled by the governor, as above described, thus causing aslight reduction in pressure within the cylinder, which assists the gases to absorb the heat of the cylinder-walls, and consequently reduce the temperature of the same whilethe engine is in operation and also reduces the clearance necessary to bring the compression-line to the proper pressure, which reduction in clearance permits the expansion to be carried to a maximum degree.

The governor G is driven from the shaft 0 as herein shown, by a bevel-gear 0 in mesh with a bevel-pinion 0" on the shaft 0 of. the said governor. I

I claim 1. In a gas-engine, the combination of the following instrumentalities, viz: a working cylinder and piston, inlet and exhaust valves therefor, and an igniter, a main shaft operated by the piston, and a cam-shaft provided with two sets of cams, one set being arranged to operate the valves and i gniter atevery revolution of the main shaft, and the other set being arranged to operate them at every other revolution of the main shaft, the cam-shaftbeing bodily movable to bring either set-of cams into operation at will, substantially as described.

2. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder, a piston therein, gas inlet and exhaust balanced piston-valves, levers connected to said valves, twosets of cams to act on said levers and movable with relation thereto at the will of the operator, springs to act on said valves in opposition to said levers, and an igniter cooperating with the gas-inlet valve, substantiallyas described.

3. In a gasengine, the combination of the following instrumentalities, viz: a main cylinder, a piston therein, a main shaft to which said piston is connected, gas inlet and exhaust valves provided with valve-rods, levers connected to, said valve-rods, a cam-shaft composed of two parts, one of which is movable longitudinally, gearing connecting said canishaft to the main shaft, two sets of cams fast on the movable part of said shaft and cooperating one at a ti mewith the levers connectedto the valve-rods, means to move the valves in the opposite direction to the'cams, and an igniter cooperating with the gas-inlet valve, substantially as described.

4. In a gas-engine, the combination of the following instrumentalities, viz: a main cylinder, a piston therein, valve-cylinders communicatin g with said main cylinder,balanced piston gas inlet and exhaust valves-in said valvecylinders provided with valve-rods, levers connected to said valve-rods,an ignitercylinder connected to the cylinder of the gasinlet valve and provided with a vent for the consumed gases, a piston in said igniter-cylinder provided with a piston-rod, a lever connected to said piston-rod, a main shaft to which the main piston is connected, a camshaft connected to said main shaft to be retated thereby and provided with a longitudi. nally-movable section, two sets of cams fast on said movable section of the cam-shaft and cooperating with the levers connected to the said gas inlet. and exhaust valvesand to the igniter-piston, .and a governorconnected to the operating lever for the gas-admission valve, substantially as described.

In testimony whereof I have signed my name to this'specification in the presence of two subscribing witnesses.

LOUIS J. HIRT.

Witnesses:

JAs. H. CHURCHILL, J. MURPHY. 

